Switch arm bending and punching machine



Jan. 10, 1967 J. G. PAHL ETAL SWITCH ARM BENDING AND PUNCHING MACHINE 4 Sheets-Sheet 1 Filed Dec. 8, 1964 INVENTORS JOHN G, Pfif/L E'M/L F; PAM.

Wym

J. G. PAHL. ETAL SWITCH ARM BENDING AND PUNCHING MACHINE Jan. 10, 1967 4 Sheets-Sheet 2 Filed Dec. 8, 1964 1967 J. G. PAHL ETAL SWITCH ARM BENDING AND PUNCHING MACHINE 4 Sheets-Sheet 3 Filed Dec. 8, 1964 Jan. 10, 1967 J. G. PAHL ETAL v SWITCH ARM BENDING AND PUNCHING MACHINE 4 Sheets-Sheet 4 Filed D60. 8, 1964 United States Patent f sesame S'WHTCH ARM RENDKNG AND PUNCHHNG MIACHENE John G. Pahl, 1524 E. Alpine Ava, Stockton, Calif. 952135, and Emil l. Pahl, 1025 Edan Ave, Stockton, Calil'f. 95207 Filed Dec. 8, 1964, $42k. No. 416,758 11 Claims. (Cl. 72214) This invention relates generally to switch arms such as are employed in pole-top disconnect switches of the type shown for example in United States Patent No. 3,144,526.

In particular, this invention is directed to, and it is a major object to provide, a novel machine for bending and forming such switch arms to the desired specific shape from an initially straight length of metal tubing.

An additional object of the invention is to provide a machine by means of which such switch arms-one at a tirne-may be quicldy and easily bent to shape by a sequence of steps, without having to manually move the tubing once it is placed in the machine to be bent.

A completed switch arm includes a dead-end, eye rod inserted into and projecting from a curved portion of the tubular switch arm tangentially thereof. It is another object of the invention to provide, as a part of the machine, a power operated punch adapted to form an opening in the tubing at the proper position for the reception of the dead-end rod, and without having to shift the tubing from the position occupied thereby in the machine while being bent.

A further object of the invention is to provide a switch arm bending and punching machine which is designed for ready and convenient operation.

A still further object of the invention is to provide a practical, reliable, and durable switch arm bending and punching machine and one which is exceedingly effective for the purpose for which it is designed.

These objects are accomplished by means of such structure and relative arrangement of parts as will fully appear by a perusal of the following specification and claims.

In the drawings:

FIG. 1 is a top plan view of the machine, showing the length of tubing as initially positioned in the machine for bending.

FIG. 2 is a similar view, but showing the tubing in its finally bent form.

FIG. 3 is an enlarged fragmentary sectional elevation of the machine, taken generally on line 3-3 of FIG. 2.

FIG. 4 is an enlarged fragmentary view of the machine, partly in section, showing the tubing punch in operation.

FIG. 5 is a fragmentary enlarged cross section taken on line 5-5 of FIG. 1.

FIG. 6 is an enlarged fragmentary longitudinal section taken on line 6-6 of FIG. 1.

FIG. 7 is an elevation of a switch arm as formed in the machine; the view being on a reduced scale.

Referring now more particularly to the drawings and to the characters of reference marked thereon, the machine for bending the initially straight length of metal tubing 1 comprises a rigid horizontal table 2 suitably supported at any desired distance from the floor. Seated on the table 2 intermediate its ends is a vertical-axis tube bending roll 3 of a predetermined diameter and formed with a peripheral groove 4 of semicircular form and the same diameter as that of the tubing 1. The roll 3 is secured on a vertical shaft 5 turnably journaled on the frame 6 of the machine below the table 2, and having a pinion '7 fixed thereon. This pinion is engaged by a horizontal rack 3 secured on the end of the piston rod 9 of a power cylinder 11) mounted on the frame 6 as shown in FIG. 3.

The tubing 1 to be bent is fed toward the roll 3in a direction tangentially thereofso as to engage in the 3,296,849 Patented Jan. 10, 1967 groove 4; the tubing being guided toward the roll 3 by a vertical axis guide roller 11 engaging the tubing on the side nearest the roll 3 and close to the same, and by another vertical axis guide roller 12 engaging the tubing 1 on the other side and spaced some distance back from the roller 11, all as shown in FIG. 1.

When the roll 3 is in its initial position, the advance of the tubing relative thereto is limited by the engagement of the adjacent or forward end of the tubing with a stop 13 mounted on said roll and projecting from the periphery thereof. As soon as the forward end of the tubing is thus engaged with the stop and seats in the adjacent portion of the groove 4, the tubing is held in such position by means of a clamping collar 14 which engages the outside of the tubing close to said stop 13. The clamping collar 14 is pivoted at its lower end on the roll 3 as at 15; said collar at its upper end and above the roll being connected to a lever and link unit 16 also mounted on said roll 3, as shown in FIG. 3. The unit 16 is arranged so that the lever 1'7 thereof when swung back or over the roll 3 will lock or clamp the collar 14 against the tubing, and when swung forward or over the collar will move the latter clear of the tubing. See FIG. 3.

The roller 11, which is peripherally grooved to engage part way about the tubing 1, is mounted in a clevis 18 of rectangular form slidably supported in a guide 1 9 fixed on the table 2 and having adjustable clevis-engaging screws 20 by means of which the clevis may be accurately positioned relative to the tubing 1. The clevis, after being thus positioned, is maintained against movement by headed clamping screws 21 which project into the guide 19 from the top of the clevis and through longitudinal slots 22 in the latter.

The roller 12, which is also peripherally grooved as at 23 to engage part way about the tubing 1, is turnably and slidably mounted on a spindle 24 mounted in and projecting between the vertically spaced arms 25 of a bellcrank 26; the spacing of the arms 25 being greater than the axial width of the roller 12, and the latter resting on the lower one of the arms when the tubing is in its initial position, as shown in full lines in FIG. 6.

The bellcrank 26 is pivoted as at 27 on a table-supported block 28 disposed clear of the path of movement of the tubing 1; the remaining bellcrank arm 29 projecting in a direction away from said tubing. The outer end of the arm 29 is connected to the piston rod 3t) of a power cylinder 31 swivelly mounted on the table 2, as at 32, for movement in a horizontal plane. The piston rod 3-6-when retractedmaintains the roller 12 in its initial tubingaguide position; the extent of advance of said piston rod, and the corresponding swinging of the bellcrank, being limited by the engagement of the arm 29 with an adjustable stop 33 on the table 2.

Mounted on the table 2 just back from the roller 12 is a somewhat elongated bar 34 projecting in a direction transversely of the tubing and away from the bellcrank 26. The upper face 35 of the bar 34 is disposed at a relatively small upward angle from its end adjacent the starting position of the initially straight length of tubing; said tubing then resting in intersecting relation on the upper face of the bar near said end thereof, and in which position the tubing is alined with the groove 4 of roll 3.

Operation After the tubing has been advanced to the roll stop 13 and is clamped in position by the collar 14, the power cylinder 10 is energized to rotate the roll 3 in a counterclockwise direction as indicated by the arrow in FIG. 2, or so as to pull the clamped tubing around with the roll and to form a curved horizonal bend 36 therein. Such tube bending operation continues until a peripheral lug 37 on the roll 3 (which lug carries stop 13) engages an adjustable stop 38 mounted on the table 2 in the path of rotative movement of said lug.

The roll 3 is then held immovable while the power cylinder 31 is energized to swing the bellcrank 26 and roller 12 in a direction to horizontally bend the tubing 1 about the roller 11 as a fulcrum, as shown at 39. This disposes the portion 40 of the tubing back from said roller 11 at an angle to the remaining straight portion 41 of said tubing and which extends from the roller 11 to the start of the curved portion 36 of the tubing, as shown in FIG. 2.

In connection with the above described bending operations, it will be noted thatafter the part-circle, tube bending rotation of roll 3-a lug 42 is mounted on top of such roll engages against the clevis 18 adjacent and above the roller 11. In this manner, said clevis is braced against the force of the subsequent tube bending movement of the bellcrank 26.

While the bend 39 is being formed, the tubing portion 40 is forced to ride along the upwardly sloping upper face 35 of the bar 34. Said tubing portion 40 is thus bent upwardly from the roller 11 at a relatively small angle to a horizontal plane and to the remainder of the tubing, as shown in FIG. 3, and for the purpose hereinafter set forth. The mounting of the roller 12 for vertical movement on its spindle 24 enables said roller to follow the upward tilting movement of the tubing portion 40 as the latter rides up the sloping surface 35, as indicated in dotted lines in FIG. 6. At the same time, however, the continued engagement of the tubing with the vertically rigid roller 11 assures against any upward bending of the tubing portion 41.

The finally bent tubingbefore being removed from the machine-is provided with an opening 43 in the outside thereof (i.e., the side opposite the roll 3) a short distance back of the clamping collar 14, as shown in FIG. 4, and hence relatively close to the adjacent open end of the tubing. This opening 43 is punched in the tubing by the following mechanism:

Mounted on the table 2 outwardly from and in axial axial alinement with the stop 13 (when the peripheral lug 37 is engaged with the stop 38) is a power cylinder 44, the piston rod 45 of which is secured to a head 46. The head is slidably engaged along its side furthest from the roll 3 by a guideway 47 mounted on the table 2. Also slidably supported by the guideway 47 independently of and in front of the head 46 is a small block 48 which is yieldably urged away from said head 46 by a spring 49 connected therebetween. The block 48 serves as a, guide for the outer end portion or tip of a head supported punch 50 prior to advance of the piston rod 45 together with head 46, and entry of the punch into the tubing 1 to form the opening 43. The advanced, opening forming position of the punch is indicated in dotted lines in FIG. 4.

The piston rod 45 is initially fully retracted together, of course, with the head 46 and punch 50. At the same time, the block 48 is fully extended relative to the head 46 by the spring 49; the tip of the punch 50 then being engaged by said block 48, as shown in FIG. 1. As the piston rod 45 is advanced, the head 46 and block 48 are advanced therewith as a unit until the block abuts against the exposed face of the tubing bend 36. Thereafter, continued advance of the piston rod 45 advances the head 46 and punch 50 only; the block 48 then maintaining the punch guided and braced at its point of initial engagement with the tubing. With such continued motion of the piston rod, head, and punch, the latter penetrates the tubing and forms the opening 43.

The purpose of the opening 43 is to provide for the reception of the cable-connecting, dead-end eye rod (not shown) with which each pole-top switch arm is provided. Such rod includes a shank inserted into the tubing through opening 43; the rod then projecting outwardly from the switch arm at the inception of and tangential to the curved bend 36 thereof; the shank of said rod being welded to the tubing about the opening 43 and at the adjacent end of the tubing.

As the tubing is closed in an airtight manner upon the dead-end eye rod being welded in place, air pockets could possibly form within the tubing and cause a dangerous condition when the subsequent hot galvanizing of the switch arm is undertaken.

To avoid such a condition, the block 46on its forward end and adjacent the side edge thereof nearest the roll 3is provided with a short, small diameter, forwardly projecting punch 51. When the head 46 is fully advanced, the punch 51 strikes an air relief hole 52 through the adjacent face of the tubing bend 36 just back from the block 48, as shown in FIG. 4.

As soon as the opening 43 and the relief hole 52 have been formed, the piston rod 45 is retracted to withdraw the punches 50 and 51, the piston rod 30 is retracted to withdraw the roller 12 from engagement with the tubing portion 40, the clamping collar 14 is released, and the finally bent and formed tubing is removed from the machine, ready for the mounting thereon of the cable-connecting, dead-end eye rod, as well as the switch part, so as to provide the finished switch arm.

Two switch arms are required to form a complete pole-top switch, and such arms are mounted on supporting brackets in opposed relation to each other; the deadend eyes being axially alined but projecting in opposite directions, and there being switch members on the adjacent outer end portions of said arms. When so mounted, means is applied to one switch arm to rotate the same relative to the other arm; said outer end portions of the switch arms and the switch members mounted thereon being disposed in overlapping relation. With such an overlapping arrangement, it has been found desirablefor eflicient switch opening and closingthat said outer end portions of the switch arms shall be disposed at a small angle to the radial plane of rotation of the movable switch arm so that the switch members, mounted on said arm portions, will be disposed at a corresponding angle. It is for this reason that the tubing 1, when being shaped to switch-arm form, is forced along the upwardly sloping face 35 of the bar 34 in order to bend the related portion of the tubing to such angle in the manner previously described.

From the foregoing description, it will be readily seen that there has been produced such a machine as substantially fulfills the objects of the invention, as set forth herein.

While this specification sets forth in detail the present and preferred construction of the machine, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described the invention, the following is claimed as new and useful and upon which letters Patent is desired:

1. A machine, for bending a length of initially straight metallic tubing, comprising a supporting table, a verticalaxis roll turnably mounted on the table, the roll having a peripheral groove of a size and shape to fit the tubing, means on the table back from the roll to engage the tubing on opposite sides and guide the same along the table tangentially of the roll and groove, a stop on the roll initially positioned to engage the forward end of the tubing when the latter is advanced to engage the groove, means on the roll to engage and clamp the tubing against retractive movement from a stop engaging position, means to rotate the roll in a direction to further advance the tubing while bending the same about the roll, and means between the roll and table to limit the extent of rotation of the roll.

2. A machine, as in claim 1, in which the tubing clamping means comprises a clamping collar disposed parallel to the axis of the roll to engage the periphery of the tubing outwardly of the roll, means pivoting the collar at its lower end on the roll, and means on the roll connected to the upper end of the collar and operable to move the collar between clamping and release positions.

3. A machine, as in claim 1, in which the guide means comprises a pair of peripherally grooved vertical-axis rollers, one on each side of the tubing and disposed in spaced relation back from the roll; the roller nearest the roll engaging the side of the tubing nearest said roll.

4. A machine, as in claim 1, in which the guide means comprises a peripherally grooved vertical-axis roller mounted in a fixed position on the table to engage the tubing on the side thereof nearest the roll, another vertical-axis peripherally grooved roller engaging the other side of the tubing back from the first named roller, means mounting said other roller in connection with the table for movement of said other roller laterally of the table in a direction to bend the portion of the tubing rearwardly of the first named roller about the latter as a fulcrum, and means to so move said roller mounting means.

5. A machine, as in claim 4, with means on the table functioning as the tubing is thus bent, to also bend said portion of the tubing relative to the plane of the table about the first named roller as a fulcrum.

6. A machine, as in claim I, in which the guide means comprises a peripherally grooved vertical-axis roller mounted in a fixed position on the table to engage the tubing on the side thereof nearest the roll, another vertical-axis peripherally grooved roller engaging the other side of the tubing back from the first named roller, means mounting said other roller in connection with the table for movement of said other roller laterally of the table in a direction to bend the portion of the tubing rearwardly of the first named roller about the latter as a fulcrum, means to so move said roller mounting means, and a bar on the table extending laterally of said tubing portion in the direction of bending thereof; the upper face of the bar having an upward slope in said direction of bending movement of th etubing and the latter initially resting on said face adjacent the low end thereof.

7. A machine, as in claim 6, in which said other roller is mounted for vertical as well as rotative movement.

8. In a machine for bending metallic tubing, a support, a tubing engaging and bending roll on the support arranged, upon rotation of the roll in one direction, to bend and wrap an end portion of the tubing thereabout, means to releasably clamp said tubing portion against movement relative to the roll, means between the support and roll to limit the tubing bending rotation of the roll and to hold the latter against further rotation in said direction, and a longitudinally movable punch mounted on the support and extending tangentially of the roll in position to punch an opening through the outer face of the tubing at a predetermined point in the length of the bent portion thereof and when the roll is held against movement.

9. In a machine for bending metallic tubing, a support, a tubing engaging and bending roll on the support arranged, upon rotation of the roll in one direction, to bend and Wrap an end portion of the tubing thereabout, a stop on the roll engaging the adjacent end of the tubing, means to limit tubing bending rotation of the roll, and a longitudinally movable punch mounted on the support tangentially of the roll and in alinement with but back from said stop when the roll is halted operative to then punch an opening through the outer face of said tubing.

10. A machine, as in claim 9, with a head on which the punch is mounted and from which the punch projects, and another relatively small punch projecting from the head in offset and parallel relation to the first named punch to the side thereof nearest the tubing; said other punch being operative to form a relative small opening in the tubing in adjacent but spaced relation to the opening formed by said first named punch.

11. In a machine for bending metallic tubing, a support, a tubing engaging and bending roll on the support arranged, upon rotation of the roll in one direction, to bend and wrap an end portion of the tubing thereabout, a stop on the roll engaging the adjacent end of the tubing, means to limit tubing bending rotation of the roll, and punching means on the support to punch an opening through the outer face of the tubing back from and tangential to said adjacent end of the tubing; said punching means comp-rising a fixed power cylinder, a piston rod projecting therefrom toward the roll, ahead on the outer end of the piston rod, a punch projecting from the head, a fixed guide for the head on the side thereof opposite the roll, a block slidably supported by the guide in front of the head and through which the punch is slidable, a yieldable spring connecting the head and block and urging the block away from the head and toward the roll for engage- 'ment with the adjacent side of the tubing upon advance of the piston rod sufficient to dispose the outer end of the punch immediately adjacent said side of the tubing at the forward end of the block.

No references cited.

WILLIAM W. DYER, JR., Primary Examiner.

LEONIDAS VLACHOS, Examiner. 

9. IN A MACHINE FOR BENDING METALLIC TUBING, A SUPPORT, A TUBING ENGAGING AND BENDING ROLL ON THE SUPPORT ARRANGED, UPON ROTATION OF THE ROLL IN ONE DIRECTION, TO BEND AND WRAP AN END PORTION OF THE TUBING THEREABOUT, A STOP ON THE ROLL ENGAGING THE ADJACENT END OF THE TUBING, MEANS TO LIMIT TUBING BENDING ROTATION OF THE ROLL, AND A LONGITUDINALLY MOVABLE PUNCH MOUNTED ON THE SUPPORT TAN- 